Fluid controlled directional bit and its method of use



Dec. 26, 1967 ANDERSON 3,360,057

FLUID CONTROLLED DIRECTIONAL BIT AND ITS METHOD OF USE Filed Dec. 1965 2Sheets-Sheet l z? j; 50g

.26 52 330 40:? Q g? 42 v 4 3,,

0 W/fl A. Ana/anion 1N VEN TOR.

BY Hagdu A; Hamel YATTORNE YS Dec. 26, 1967 A. ANDERSON 3,360,057

LUID CONTROLLED DIRECTIONAL BIT AND ITS METHOD OF USE Filed Dec. 6, 19652 Sheets-Sheet 2 [Mn m A. Jade/u 0/1 32 6 J5 LVVENTOR.

b 39 35v BY (g 37 JTTORXEYS United States Patent 3,360,057 FLUIDCONTROLLED DIRECTIGNAL BIT AND ITS METHOD OF USE Edwin A. Anderson, 1104Chimney Rock Road, Houston, Tex. 77027 Filed Dec. 6, 1965, Ser. No.511,773 8 Claims. (Cl. 175-67) This invention relates to a new andimproved apparatus and combination for jet deflection drilling, and moreparticularly, to a new and improved drill bit for jet deflectiondrilling and a new and improved combination used in conjunction with thedrill bit to provide better jet deflection drilling.

Heretofore, when it was desired to directional drill, it has beennecessary to use a whipstock, which device is well known in the art, setin a borehole. The whipstock functions to guide the drill "bit againstthe side wall of the borehole and deflects the bit to drill the boreholefrom its original path in any desired direction.

The use of a whipstock is very burdensome and time consuming because ofthe many round trips that must sometimes be made from the drilling rigat the surface of the earth into the borehole. For example, to use thewhipstock, it must initially be set in the borehole; and after thewhipstock is seated in place in the well bore, survey instrurnents arelowered into the well bore to determine the direction in which thewhipstock is facing. If necessary, the drill string is moved andadditional surveys taken until the whipstock is facing in the desireddirection. This operation is well known in the art.

Thereafter, the drill string is drilled off the face of the whipstock,the whipstock removed, and the deflected portion is then reamed andsurvey instruments again lowered to determine if the deflection issatisfactory. If not, then the drill string is removed and a whipstockconnected thereto and again lowered and the Whole operation repeated.

This procedure is well known in the art and can be very expensive andtime consuming where more than one deflection is required beforeobtaining the desired deflection of the well bore.

There are also other known methods of deviating a borehole by deflectiondrilling, such as jet deflection methods, wherein, for example, two ofthree jet nozzles in a drill bit may be restricted, plugged, or blankedoff by inserts while leaving the third jet nozzle unrestricted forflowing more well fluid therethrough to deviate the borehole.

However, there are certain problems with structures presently used inthis type of jet deflection drilling because there are no means providedto remove the restrictions, plugs, or blanks in the drill bit afterdeflection of the well bore and while the bit is still in the Well boreto enable ordinary drilling to proceed, and thereafter reinsert theplugs, restrictions, or blanks while the bit is still in the well boreto accomplish subsequent deflection, if desired.

Another problem often encountered in using present structures for jetdrilling is that after the jet deflection operation is completed, thereis sometimes a tendency for the two restricted jet nozzles in the drillbit to stop up with mud and debris, thus hindering the normal drillingoperations.

An important object of the present invention is to provide a new andnovel drill bit which is partitioned so that it may be employed toaccomplish normal drilling operations and which may also be employed,when desired, to jet deflect a well bore.

It is also an object of the present invention to provide a new andimproved jet deflection arrangement wherein 3,360,057 Patented Dec. 26,19$? the drill string or any portion thereof need not be removed fromthe well bore to control the drilling operations after deflection andduring continued normal drilling operations.

A further object of the present invention is to provide in a drill bithaving multiple jet cutters and multiple jet nozzles a partition meanswithin the bit to enable all of the drilling fluid to flow through allof the nozzles during normal drilling operation, or to selectively flowall of the drilling fluid through only one nozzle in the drill bit toaccomplish jet directional drilling with the bit.

It is another object of the present invention to provide a new andimproved jet deflection apparatus for use with a two or three cutterdrill bit having jetting nozzles where in when it is desired todirectionally drill, one of the jet nozzles may be used for directionaldrilling by closing off the remaining nozzles with a retrievableassembly.

It is another object of the present invention to provide a new andimproved jet deflection apparatus wherein there is provided a new andimproved drill bit with nozzles that do not have to be permanentlyplugged or restricted to accomplish directional control of the bit.

It is an important object of the present invention to provide a new andimproved drill bit which may have either two or three cutters andadjacent jetting nozzles in which there is provided a partition meansfor directing fluid flow through all of the nozzles except the one usedto directional drill.

It is another object of the present invention to provide a new andimproved jet deflection apparatus wherein there is provided a noveldrill bit construction including an arrangement which permitsselectively closing two of the nozzles of a three nozzle drill bit andthereby permits jet deflection drilling on one side of the borehole andwhich thereafter permits opening the two nozzles for ordinary drillingoperations and, if desired, to again close oflf the two nozzles forfurther directional drilling.

It is another object of the present invention to provide a new andimproved arrangement for jet deflection drilling wherein there isprovided a nonmagnetic drill collar adapted to be secured to a new andnovel drill bit, the drill collar having magnets therein for orienting asurvey instrument relative to the magnets and the unrestricted nozzle inthe drill bit, a retrievable drop ball assembly for seating on the drillbit to thereby close all but one nozzle of the drill bit to thereby flowall of the drilling fluid through the remaining open nozzle to jetdeflect the well bore when the rotation of the drilling string isstopped.

Yet another object of the present invention is to provide a drilling bitwhich may be used for jet deflection drilling and which also uses largerjetting nozzles during ordinary drilling operations than generally usedheretofore and thereby increases the rate of drilling during ordinarydrilling operations by increasing the rate of circulation ofdrillingfluid to move the cuttings off bottom.

Still a further object of the present invention is to provide a drillingbit for jet deflection drilling which is constructed and arranged sothat the rate of circulation of drilling fluid is increased duringnormal drilling operations above that generally possible with presentjet deflection bits to thereby aid in keeping the bit teeth cleaner andaid in increasing the rate of penetration 'by more quickly moving thecuttings away from the bottom of the borehole to inhibit regrindingthereof.

In accordance with the present invention, there is provided a means andarrangement for corrective drilling of a well bore that does not requirewhipstocks. In the apparatus, deflection of the drill string is obtainedby directing all of the drilling fluid through one nozzle of a jet drillbit. Of course, it is to be understood in the normal usage of a drillbit in jet deflection drilling that the jetting nozzle will be adjacentthe side of the well bore where it is desired to deviate; and thedeviated well bore may be in any desired direction. The novel drill bitof the present invention is adapted to be secured to a nonmagnetic drillcollar so that a survey instrument may be lowered to position inside thenonmagnetic drill collar to permit a shot or picture of the well bore tothereby align the jetting nozzle for proper deviation of the well bore.There is also provided a retrievable drop ball assembly for seating onthe drill bit to selectively close all but one nozzle of the drill bitand which may thereafter be removed when normal drilling operations aredesired to thereby open all nozzles in the drill bit which results insubstantial savings because the drill string need not be removed fromthe well bore to thereafter open or close the nozzles and be cause therate of circulation of drilling fluid during normal drilling operationsis increased over that generally possible with jet deflection bitspresently employed.

Other objects and advantages of the present invention will becomeapparent from the following detailed description of the invention takenin conjunction with the accompanying drawings which form an integralpart of this specification and wherein:

FIG. 1 is a broken sectional view representing a well bore and drillstring therein with a drill bit in partial sectional view connected tothe lower end of the drill string and showing in elevation theretrievable drop ball assembly seated on the bit and a survey instrumentseated on the drop ball assembly to determine the direction in which thelargest jet nozzle of the bit is facing;

FIG. 2 is a broken sectional view representing a well bore and drillstring therein with a drill bit in partial sectional view connected tothe lower end of the drill string and showing in elevation theretrievable drop ball assembly seated on the bit and whereby all of thedrilling liquid is conducted through the largest jet nozzle toaccomplish deflection of the well bore;

FIG. 3 is a broken cross-sectional view of a well bore with the drillstring and drill bit in partial section and illustrating the well boreafter it has been deflected and the retrievable drop ball assemblyremoved so that ordinary drilling operations may continue;

FIG. 4 is a persepective view illustrating the preferred form of thedrilling bit of the present invention;

FIG. 5 is a view illustrating the partition means in the drill bit ofthe present invention as being in the form of an inverted Y-shaped tube;

FIG. 6 is an enlarged view in cross-section illustrating in greaterdetail a preferred form of the drilling bit of the present invention;and

FIG. 7 is a perspective view showing another form of the partition meansof the present invention.

It is, of course, to be understood that while FIGS. 1 to 4 and 6illustrate a drilling bit with three cutters and three nozzles, thepresent invention is not limited in any way to a drill bit with threecutters and three nozzles; but, of course, may include, for example, atwo cutter and two nozzle drill bit or any number of multiple cuttersand multiple nozzles.

Referring now to the drawings, there is illustrated in FIG. 1 a wellbore represented generally at 1 drilled with a drilling rig (not shown)wherein the means used to drill the well bore is a conventional drillstring represented generally at In including drill collars therein and adrill bit 30 on the lower end thereof. The drill collar immediatelyadjacent the bit 30 as illustrated in FIG. 1 is a nonmagnetic drillcollar 2 which is provided with a plurality of magnets 3, 4, and 5 thatare used for orienting a survey instrument 20 in a manner well known inthe art. Of course, there may be a number of drill collars connectedabove the nonmagnetic drill collar 2 in the drill string 1a; and theuppermost drill collar is secured at its upper end 2a to the last jointof drill pipe in drill string 1a by means of threads 6 and 7 on theuppermost drill collar and lowest or last drill pipe joint,respectively. The lower end 215 of the nonmagnetic collar 2 is securedby means of threads 8 to a sub 20 which, in turn, is connected to thedrill bit 34) by threads 2d and 31 on the sub and bit, respectively.

A drill bit 30 is shown in FIGS. 4 and 6 with three cutters designatedgenerally at 50' and each cutter having teeth thereon of anyconventional form.

The drill bit body is represented generally by the numeral 32 and isconstructed to receive thereon the cutter means, which may be of anysuitable form such as a rolling cutter as represented at 50' and ishollowed to provide openings for receiving jet nozzles in the bit bodyas will be described. The drill bit 30 as illustrated in the drawings atFIGS. 4 and 6 is represented as having three cutters 5i) and is providedwith a fluid passage means 33 with in its body 32 which extends throughthe portion 30a and is open at the upper end of the drill bit 30 forreceiving drilling fluid from the drill string 10. The bit body 32 isformed internally so that the passage means 33 is split into three fluidpassageways 32a, 32b, and 320 for directing or discharging drillingfluid out the lower end of the bit body 32 as will be described.

The portion 30a on the drill bit body 32 is provided with threads 31,previously mentioned, for receiving with the threads 2d on the sub 20,the threads terminating at the surface designated generally at 32d.

The drill bit 30 of the present invention is provided with a partitionmeans, one form of which is illustrated generally at 40 in FIGS. 4, 5,and 6 for directing drilling fluid through the drill bit in a selectivemanner to accomplish the desired results as will be described in greaterdetail.

The partition means 40 represented in FIGS. 4 to 6 is shown as being inthe form of an inverted Y-shaped tube which is forked at 41 to therebyform a single hollow tube or channel 42 facing upwardly within the drillbit 30 and two hollow tubes or channels 43 and 44 facing downwardly inthe drill bit 30 and communicating respectively with the fluidpassageways 32c and 32b, respectively. In the arrangement of the drillbit 30, as shown in FIGS. 4 to 6, the inverted Y-shaped tube orpartition 40 is positioned within the drill bit body 32 as it isassembled so that the tubes 44- and 43 may be secured by any suitablemeans such as by welding to the inner surface 34 of the drill bit body32; and when so positioned, it assumes the relationship illustrated indotted lines in FIG. 4 and more easily viewed in FIG. 6. It will benoted that the channels 43 and 44 communicate, respectively, aspreviously noted, with fluid passageways 32c and 32b, respectively, andthe single hollow tube 42 extends upwardly within the portion of thepassageway 33 that faces upwardly in the drill bit body 32 as shown inFIG. 6.

The tube 42 is smaller in diameter than the portion of the passageway 33in which it is received, thereby forming an annular passage 33a withinthe drill bit body 32 that communicates with fluid passageway 32a asmore clearly seen in FIG. 6.

Nozzle inserts 35a, 35b, and 350 are received within each of thepassageways 32a, 32b, and 320, respectively; and each insert is formedwith an opening 35, 37, and 38 for discharging drilling fluidtherethrough with a jetting action. Each insert 35a, 35b, and 35c isprovided with an O-ring seal 36, 39, and 46, respectively, so that whenthe insert is seated in its respective fluid passage leakage therearoundis inhibited. The nozzle inserts are formed of suitable material wellknown in the art and may be held in position in each passageway by meanswell known, such as snap rings.

With the partition means 40 arranged as illustrated in FIG. 6, nozzleopening 35 in nozzle insert 35a is substantially larger than nozzleopenings 37 and 38 in nozzle inserts 35b and 350, respectively.

A seat 40a is formed on the end of the tube 42 for re ceiving means 50thereon as shown in FIG. 2 which closes off flow through passageways 32band 32c so as to direct all drilling fluid through fluid passageway 32a.Also, such seat 40a serves as means whereby the survey instrument 20 maybe positioned in the drill string since the means 50 serves also as ameans for spacing the instrument 20 when it is lowered into the drillstring.

Thus, to directionally drill or to use the present invention fordirectional drilling, it is only necessary to cap or close the upper endof tube 42. This prevents flow of drilling fluid through the passageways32b and 32c and also prevents fluid discharge from openings 37 and 38 ofjet nozzle inserts 35b and 350 while directing all the flow of drillingfluid through annular passage 33a for discharge through the largeropening 35 of nozzle insert 35a to jet away the side of the well bore inwhich the jet nozzle insert 35a is oriented, and, therefore, the drillstring 1a begins deviating in the direction in which jetting nozzle 35ais digging. It should be noted that while directionally drilling, thedrilling string 1a is not rotated.

To further amplify and describe the use of the present invention,attention is first directed to FIG. 1 of the drawings wherein the drillstring 1a is shown as having a nonmagnetic drill collar 2 connected bymeans of sub 20 to bit 30 constructed in accordance with the presentinvention. At the time that the drill bit 30 is connected by sub 20 tononmagnetic collar 2, the angular relationship be tween the magnets 3,4, and 5 and the larger jet nozzle opening 35 is determined at theearth's surface before lowering the bit into the well bore.

After the bit 30 is on bottom in the well bore, a retrievable drop ballassembly 50 is pumped down the drill string 1a to rest on seat 46aformed on the end of tube 42 in drill bit 30.

The drop ball assembly 50 is provided with a fishing head 51 and servesas a spacer so that when survey in strument 20 is lowered on wireline 21in drill string 1a, the spring arms 23b and 230 engage head 51 andposition the survey instrument properly within nonmagnetic drill collarrelative to magnets 3, 4, and 5 so that a determination may be made in awell-known manner in the art as to the direction in which the largernozzle opening 35 is facing, such nozzle opening being termed a big eyejet in the art to which the invention pertains.

It can be appreciated that the spring arms 23b and 230 could be tiedtogether so that when the survey instrument 20 is lowered into the wellbore, they would rest on the top of head 51 and thereby not engage means50 and cause it to be removed from the drill string each time surveyinstrument 20 is run.

The survey instrument is retrieved to the earths surface; and if thesurvey indicated that the big eye jet is not facing in the desireddirection, the drill string 1a is moved and the foregoing operationrepeated until the survey indicates that the larger nozzle opening 35 orbig eye jet is properly positioned in the well bore.

It should be noted that the survey instrument is of wellknownconstruction and secured thereto is the retrieving tool 23 which isconnected to the survey instrument 20 by the threaded shaft 23a.Radially extending arms 23d on tool 23 and on means 50 position eachwithin the drill string 1a. The means 50 in the form shown includesfishing head 51 to which is connected shaft 53 with a seat member 52 onthe lower end thereof for seating on seat 40a formed in the drill bit30.

After the big eye jet is properly positioned in the Well bore, theretrievable drop ball assembly 50 is pumped down the drill string andseated as shown in FIG. 2 and all of the drilling fluid is directed tothe big eye jet so that without rotating the drill string 1a, the wellbore adjacent the big eye jet may be cut away as illustrated generallyat 60. The jetting operation may continue until it is determined byadditional surveys by means of instrument 20 that the well bore 1 hasbeen deviated the desired amount. Of course, as jet deflect-ion isaccomplished, the operator lowers drill string 1a. When the desiredamount of deviation has been accomplished, the drop ball assembly 50 maybe retrieved from the drill string when the survey instrument '20 andretrieving tool 23 are lowered into the well bore to take a picture.Thereupon, normal drill operations may continue with drilling fluiddischarging through all jet nozzles and upon rotation of the wellstring. This is illustrated in FIG. 3 of the drawings wherein drillingfluid is discharged through all of the nozzles.

If it should thereafter become necessary or desirable to further deviatethe well bore, it may be accomplished by first positioning the big eyejet in the proper direction, as previously described hereinabove, andthen dropping ball assembly 50, as previously described, so that jetdeflection may be accomplished. Of course, as the well bore is deviatedby jetting action, the operator will lower the drill string 1a, aspreviously noted. Thereafter, the drop ball assembly may be retrieved,whereupon normal drilling operation may again continue.

It should be readily apparent that since the smaller nozzle inserts 35band 350 do not have to be restricted, blanked, or plugged duringdirectional drilling with the present invention, the nozzle openings '37and 38 therein may be larger than nozzle openings that have to berestricted, blanked, or plugged in a directional jet bit such asgenerally presently employed. I

This should enable normal drilling operations to proceed at an increasedrate after jet deflection since a larger opening may be used in theinserts 35b and 35c than generally heretofore possible, and thus anincreased rate of drill fluid may be maintained during normal drillingoperations. The increase in drilling fluid circulation moves thecuttings ofl. bottom faster and aids in preventing regrinding of thecuttings and aids in keeping the teeth on the cutters 50' cleaner. Also,since the present invention enables larger openings to be used in theinserts, restric tion, or clogging thereof is greatly reduced.

Referring again to FIG. 3, the well bore has been deviated an angle 9from the vertical; and the arrows indicate that fluid is flowing throughthe partition means 40 and the annular space 33a so that all of thenozzle openings are emitting fluid therethrough. As brought outhereinabove, since the nozzle openings 37 and 38 do not have to "berestricted, blanked, or plugged, the openings 37 and 38 are larger thanblanked, restricted, or plugged nozzles generally in use at the presenttime; and this increases the rate of circulation of fluid in the bottomof the borehole which removes the cuttings from the borehole as soon asthey are cut and which also keeps the teeth of the cutters, the nozzleopenings, and the bottom of the borehole clean and unclogged. 1

Additionally, if it is desired to deviate the well bore after drop ballassembly 50 has been removed, it need only be pumped down as beforedescribed and the big eye jet oriented in the well bore and jetdeflection drilling may then proceed.

'Another embodiment of the partition means is illustrated in FIG. 7.This partition means 140 is similar in function to the partition means40 previously described but diflers structurally. For example, insteadof separate channels or tubes to selected jet nozzles, there is a singlehollow member or shell 142 which may be welded in place in a drillingbit so that the lower open end 143 of the member 142 surrounds one ormore openings and there by isolates the opening or openings which itsurrouiids.

For example, in a three jet nozzle drilling bit, the member 142 issecured in the drilling bit so as to surround two of the nozzles andthereby isolate them from the third jet nozzle. On the other hand, in atwo jet nozzle bit, the member 142 would surround only one nozzle toisolate it from the other. The member 142 is provided with a seat awhich serves the same functions as those noted with regard to seat 40a.

It is apparent that various modifications could be provided withoutdeparting from the scope of my invention.

Broadly, the present invention relates to a partitioned jet deflectiondrilling bit and its method of use wherein drilling fluid may be passedthrough all of the nozzles or through only one of the nozzles, asdesired.

'What is claimed is:

1. A drill bit adapted to be connected to a drill string including:

(a) a body,

(b) cutter means mounted on the lower end of said body,

() said body being hollowed to form fluid passage means therein forreceiving drilling fluid from the drill string,

(d) said passage means extending through said body to form a pluralityof separate discharge passages for discharging fluid from the bit,

(e) jet nozzle inserts in each of said discharge passage means,

(f) partition means in said passage means for separating fluid flow fromthe drill string to conduct it to all but one of said dischargepassages, and

(g) se-at means formed on the upper end of said partition means forreceiving a closure member thereon whereby all of the drilling fluid maybe directed to said one discharge passage.

2. The invention of claim 1 wherein said partition means includes:

(a) a tubular member extending upwardly within said passage means formedin said bit,

(b) said member having a smaller diameter than the passage means to forman annular passage therebetween, and

(c) channel means connected to the lower end of said member andextending into all but one of said discharge passages formed in saidbit.

3. The invention of claim 2 wherein said annular passage communicateswith said discharge passage in which there are no channel means wherebywhen said seat formed on said partition is provided with a closuremember, all of drilling fluid is conducted through said annular passageand discharge passage in communication therewith.

4. In a drill bit adapted to be connected to a drill string forreceiving drilling fluid therefrom:

(a) a plurality of nozzles mounted in said bit and each having anopening therein for discharging the drilling fluid out the lower end ofsaid bit,

(b) fluid conducting passage means formed in said bit for conductingdrilling fluid to said nozzles, said fluid conducting passage meansincluding:

(1) partition means for conducting drilling fluid to two of said nozzlesand for conducting fluid separately to one of said nozzles, and

(c) said one nozzle to which fluid is separately conducted having asubstantially larger opening whereby selective communication of all thedrilling fluid therethrough enables the drill bit to function as adirectional drilling device.

5. In a rotary drill bit adapted to be connected to a drill string andused for directional drilling of a Well bore with fluids comprising:

(a) a body,

(b) means on said body for cutting the well bore when the bit isrotated,

(c) a plurality of nozzles positioned on said body,

(d) said nozzles having openings for ejecting fluid from the bit,

(e) passage means formed in said bit for conducting fluid to all of saidnozzles,

(f) partition means in said bit so that fluid may be conductedseparately to one of said nozzles,

(g) a seat on said partition means for receiving a closure thereonwhereby all of the drilling fluid may be conducted to said nozzle, and

(h) said one nozzle to which fluid is conducted separately having anopening substantially larger than said other nozzle openings wherebyfluid passage only through said one nozzle enables said bit to drilldirectionally when said bit is not rotated.

6. The invention of claim 5 wherein said partition means includes a tubeextending upwardly in said bit and having an annular seat thereon forreceiving a closure member whereby all the drilling fluid may beconducted to said one nozzle.

7. In a drill bit adapted to be connected to a drill string forreceiving drilling fluid therefrom:

(a) a plurality of nozzles mounted in said bit and each having anopening therein for discharging the drilling fluid out the lower end ofsaid bit,

(b) fluid conducting passage means formed in said bit for conductingdrilling fluid to said nozzles,

(c) partition means in said body for separating fluid flow in saidpassage means to conduct drilling fluid to two of said nozzles and forconducting fluid separately to one of said nozzles, and

((1) said one nozzle to which fluid is separately conducted having asubstantially larger opening whereby selective communication of all thedrilling fluid therethrough enables the drill bit to function as adirectional drilling device.

8. A method of drilling a well bore comprising the steps of:

(a) securing a drill bit to a drill string wherein the drill bit isprovided with a plurality of jet nozzles, one of which is substantiallylarger than the others,

(b) lowering the drill string with the drill bit thereon into a wellbore,

(c) lowering a survey instrument and spacer means to seat on the drillbit and aligning the large jet nozzle in a predetermined direction inthe well bore,

(d) removing the survey instrument from the drill string,

(e) the spacer means also functioning to close ofl fluid flow to all ofthe jet nozzles except the large one,

(if) deviating the well bore by jet deflection,

(g) removing the spacer means and thereafter continuing normal rotarydrilling operations,

(h) subsequently jet deflecting the same well bore by replacing thespacer means and survey instrument to first align the larger jet nozzlein a predetermined manner in the well bore,

(i) thereafter removing the survey instrument to enable jet deflectionof the well bore to proceed, and

(j) removing the spacer means and thereafter continuing normal rotarydrilling operations.

References Cited UNITED STATES PATENTS 2,142,559 1/1939 Duus 175452,686,660 8/1954 Storm 175-45 X 2,873,092 2/ 1959 DWyer 175-340 X 2,945,678 7/ 1960 Doudrea'ux 175340 X 3,195,660 7/1965 McKnown l339 X CHARLESE. OCONNELL, Primary Examiner, NILE C. BYERS, Examiner,

8. A METHOD OF DRILLING A WELL BORE COMPRISING THE STEPS OF: (A)SECURING A DRILL BIT TO A DRILL STRING WHEREIN THE DRILL BIT IS PROVIDEDWITH A PLURALITY OF JET NOZZLES, ONE OF WHICH IS SUBSTANTIALLY LARGERTHAN THE OTHERS, (B) LOWERING THE DRILL STRING WITH THE DRILL BITTHEREON INTO A WELL BORE, (C) LOWERING A SURVEY INSTRUMENT AND SPACERMEANS TO SEAT ON THE DRILL BIT AND ALIGNING THE LARGE JET NOZZLE IN APREDETERMINED DIRECTION IN THE WELL BORE, (D) REMOVING THE SURVEYINSTRUMENT FROM THE DRILL STRING, (E) THE SPACER MEANS ALSO FUNCTIONINGTO CLOSE OFF FLUID FLOW TO ALL OF THE JET NOZZLES EXCEPT THE LARGE ONE,(F) DEVIATING THE WELL BORE BY JET DEFLECTION, (G) REMOVING THE SPACERMEANS AND THEREAFTER CONTINUING NORMALLY ROTARY DRILLING OPERATIONS, (H)SUBSEQUENTLY JET DEFLECTING THE SAME WELL BORE BY REPLACING THE SPACERMEANS AND SURVEY INSTRUMENT TO FIRST ALIGN THE LARGER JET NOZZLE IN APREDETERMINED MANNER IN THE WELL BORE, (I) THEREAFTER REMOVING THESURVEY INSTRUMENT TO ENABLE JET DEFLECTION OF THE WELL BORE TO PROCEED,AND (J) REMOVING THE SPACER MEANS AND THEREAFTER CONTINUING NORMALROTARY DRILLING OPERATIONS.